What target should I prioritize?

Ok - 50yr old, overweight wanabe. Been using Systm for a while now - really enjoying it.
Using it to compliment training for some upcoming sprotives.
Wired up with loads of sensors and really enjoy training to that structure.

My observation is - I seem to have no real issue hitting power and cadence targets, but what I notice is two things regarding heartrate.

  1. On intensity Z3/4 portions of a training slot, I cannot seem to get my heart rate up into that zone - that is the most frequent observation.
  2. For the Z2 recovery parts of a training episode, if I do manage to get into Z3, I’m slow to get back down into Z2.
    So - should I be configuring the tool to do x% more of my recorded FTPs(done with the tests) in order to set the power zones higher?

It almost feels the zone ranges for power and heart are misaligned for me - note I take these ranges from semi-regular 4DP tests.

I guess what I’m curios about is - is it the power or the heart rate that takes priority when I’m trying to tune/configure the app?
Warm regards


Over HR, power, always.

HR targets are slower to react. Many have found them too low in many cases and you won’t be alone in being a bit slow to return to Z1-2 after a z4-5 effort.

Welcome to the forums Tom @tom_counihan


Thanks for the prompt response Glen.
I’m not 100% confident about understanding your first sentence -“Over HR…” - are you saying Power is the key metric to be focused on and HR is secondary?
Actually - what I’m more interesting is in figuring out how to get my HR into the higher zones 3/4/5 when called upon. I sometimes wonder/feel that when the session calls for it - higher intensity - that I am somehow not getting the full benefit of the session if I don’t get my HR into those higher ranges - I think that is the real core to my query.
thanks again.

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If you WANT to get your HR higher, turn off ERG mode, use level mode and give it all the beans.

Edit: I should add that the full benefit will be gained, even if your HR doesn’t match the targets in the sessions. If you are regularly reassessing via Full Frontal, or at a minimum, Half Monty and you’re making improvements just keep doing what you’re doing.


Yep, HR is slow to respond and variable. As fitness increases, HR changes more quickly, but still lags significantly. Viewing the HR graph during the workout allows seeing how your HR is trending during intervals and during the workout and to see if it’s trending in the right directions. You can chose to display your heart rate graph in the workout settings. Unfortunately, in SYSTM, you can only see one graph at a time. It’d be really helpful if the workout player would show the HR graph over the power graph as us possible in all other apps I’ve used.


In general HR can vary for a number of reasons, and at best is just a measure of input. In general (there are important exceptions), power is a measure of output, and and is what you are trying to improve.

There are people much younger than I, who can reach much higher HR, but whose power is less than mine.


In my experience, it seems that HR is slower to respond with age. As a 64-year-old, I am still able to get a pretty high-for-my-age cTHR (170 as measured in my most recent FF four weeks ago) but it takes me quite a while to move up or down in response to changes in Sufferfest workouts. Seems I’ve also been told that HR is more of a lagging indicator, so the immediate change to the target HR that comes up for intervals on SYSTM is plain unrealistic, especially for the recoveries that often show Z1 for the target. I’m usually just getting back to Z1 after a five minute cool down.

Apologies if I’m just repeating what others have written here!


Certainly HR is a lagging indicator, but it is often useful as an indicator of fatigue.

I am older than you are, and I never get down to Z1 between intervals as the software settings would have you believe possible.


yep. You have to pay close attention to cardiac drift or you can get into overtraining real quick. Bad things happen if you keep going.

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Sometimes the opposite is true, fatigue can be present if you cannot get your heart rate up when it should.

I usually find that having cardiac drift in one workout is not usually an issue. I worry when it happens more than once, and there is no explanation such as dehydration.

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